The Earth's core consists of black metal. But I am uncertain if that is the black sun being referenced, as the entire submission is a series of 'what if' scenarios, based on pure speculation and fanciful trysts in writing.

look into: "black sun" " black cube" "saturnalia" " Saturn worship" it's a long hole you'll stumble into

Before sun worship supposedly ancient man worshipped Saturn or so the theory goes. An interesting dig none the less. Saturnalia.